Toe iron for safety ski bindings



Oct. 24, 1967 MARKER 3,348,856

TOE IRON FOR SAFETY SKI BINDINGS Filed June 17, 1966 5 Sheets-Sheet 1 ATTORNEYS I Oct. 24, 1967 7 Q. MARKER 3,348,856

TOE IRON FOR SAFETY SKI BINDINGS v Filed June 17, 1966 5 Sheets-Sheet 2 INVENTOR HANN ES MARKER- BY WBMM/M ATTORNEYS Oct. 24, 1967 MARKER I 3,348,856

TOE IRON FOR SAFETY SKI BINDINGS Filed June 17, 1966 5 Sheets-Sheet 5 INVENTOR HANNES MARKER L Q M ATTORNEYS Oct. 24, 1967 H. MARKER 3,348,856

TOE IRON FOR SAFETY SKI BINDINGS Filed June 17, 1966 5 Sheets-Shet 4 INVENTOR HANNES MARKER BY mflmmfw ATTORNEYS Oct. 24, 1967 MARKE 3,348,856

TOE IRON FOR SAFETY SKI BINDINGS Filed June 17, 1966 5 Sheets-Sheet 5 INVENTOR HANNES MARKER BY mfi mgw ATTORNfiYS United States Patent TOE IRON FOR SAFETY SKI BINDINGS Hannes Marker, Hauptstrasse 51-53, Garmisch- Partenkirchen, Germany Filed June 17, 1966, Ser. No. 558,464 Claims priority, application Germany, June 21, 1965, M 65,666 Claims. (Cl. 28011.35)

It is an object of the invention to provide in ski bindings a safety toe iron which resiliently absorbs by a large cushioning movement the forces which occur transversely to the longitudinal direction of the ski so that slight lateral shocks, as often occur during skiing, do not cause an unintended release whereas the stronger forces acting on the leg during a twisting fall overcome the cushioning resistance so that the foot is released. The toe iron according to the invention should be designed so that an adjustment of the spring force is not required, a firm hold of the foot is ensured even in the normal position, and there is no undesirable interaction between the cushioning spring of the toe iron and the spring of the tightener, which urges the foot in the longitudinal direction of the ski against the toe iron.

This object is accomplished according to the invention by a toe iron which is characterized by a combination of the following features:

(1) The sole holder of the toe iron is movable only transversely to the longitudinal direction of the ski for a large distance until the release position has been reached .and is then capable of a guided forward movement;

(2) A return spring tends to return the sole holder to its normal position in any position of the sole holder;

(3) The return spring is a prestressed rubber tension spring having a very low spring rate and is secured to two eyes, one of which is carried along at a time by a movement of the sole holder whereas the other is retained in its initial position.

The use of a rubber tension spring, which consists preferably of a sleeve and which is secured under initial stress to the retaining eyes, ensures a sufficiently strong spring resistance even during the initial movement of the sole holder from its normal position. The resistance of the spring does not substantially increase throughout the cushioning movement. The foot is not held by a relatively small force in its intermediate position, as in the known toe irons, where the, spring resistance increases greatly before the release and must be only so high that even this higher spring resistance can be overcome during a fall. As the toe iron is not rotated about an axis which is at right angles to the surface of the ski, but is displaced transversely to the longitudinal direction of the ski, the force of the tightener does not urge the foot forwardly during lateral movements. In thi case, the return spring would have to act against the tightener spring. The mounting of the sole holder for a movement in a transverse direction ensurses also that it is not necessary to push the foot back against the resistance of the tightener spring when the release movement in initiated, as with the known safety toe irons which rotate about an axis at right angles to the ski. The large cushioning movement and the low spring rate of the prestressed rubber spring which is used according to the invention eliminate the need for an adjustment of the spring force because the relatively high initial force ensures that even a fairly strong skier is sufficiently held in the binding whereas the large cushioning movement and the flat spring rate enable a movement beyond the cushioning distance and a release of the foot even in the case of very light persons.

3,348,856 Patented Oct. 24, 1967 'ice Further features of the invention will become apparent from the following description with reference to the drawings, which show two embodiments by way of example. In the drawings:

FIG. 1 is a sectional side elevation showing a first embodiment,

FIG. 2 is a top plan view showing the embodiment of FIG. 2,

FIG. 3 is a sectional side elevation showing the rubber spring used according to the invention and its mountings,

FIG. 4 is a top plan view showing the spring mountings,

FIG. 5 is a view similar to FIG. 5 but with the toe iron released,

FIG. 6 is a sectional side elevation showing another embodiment of the invention, I

FIG. 7 is a top plan view showing the embodiment of FIG. 6, and

FIG. 8 is a top plan view showing the embodiment of FIG. 6 in released position.

In the embodiment shown in FIGS. 1 to 5, spring mountings 8 and 9 are inserted in a baseplate 25 and have interdigitating, forked guides 21 and 22 bearing on stops 18, 19 of baseplate 25. A rubber spring 7 is held under initial stress by pins 15, 16 in the upturned lateral lugs of spring mountings 8, 9. Details of these spring mountings are apparent from FIGS. 3 and 4.

An extension 20 of a sole holder 2 is disposed between the two upturned lugs of spring mountings 8, 9 and extends over their forked guides 21, 22. Sole holder 2 has guide cams 3, 4 bearing on guide cams 5, 6 of a cover plate 1. Cover plate 1 and baseplate 25 are jointly secured to the ski by screws 26 to prevent a lifting of sole holder 2 and spring mountings 8, 9. Further means to prevent a lifting comprise a screw 27, by which baseplate 25 is additionally secured to the ski. Baseplate 25 is provided in its rear portion with a flange 29, which extends over a cam 28, which is secured to an extension 20 of sole holder 2. This arrangement affords additional means preventing a lifting of sole holder 2. Sole holder 2 is held in a slot 12 of cover plate 1 and additionally guided by a roller 11, which is mounted on a pin 10, which is secured in extension 20 of sole holder 2.

In response to a force which is transverse to the longitudinal direction of the ski, sole holder 2 and its extension 20 perform a lateral movement, in which they are initially guided in a transverse direction by guide cams 3-6 and by roller 11 and slot 12. During this lateral movement of sole holder 2, the extension 20 thereof is urged against one of the spring mountings 8 and 9 so that this mounting 8 or 9 is also displaced transversely to the longitudinal direction of the ski and the stress on rubber sleeve 7 is increased. To insure a satisfactory displacement of spring mountings 8, 9, a friction-reducing layer 17 is provided between baseplate 25 and forked guides 21, 22. When the foot has reached a predetermined angular position, guide cams 3, 4 can slide in contact with guide cams 5 and 6 into recesses 23 and 24. As roller 11 can yield simultaneously into one of the forwardly directed cam slot branches 13 and 14, sole holder 2 can now move toward the tip of the ski so that the boot is released. The release position is shown in FIG. 5 When the transverse force is discontinued, the rubber spring returns spring mountings 8, 9 to their initial position so that the forked guides 21, 22 bear again on stops 18, 19 and sole holder 2 and its extension 20 are urged back to their initial position.

FIGS. 6 to 8 show a further embodiment of a toe iron according to the invention. Spring mountings 48, 50 are again inserted in a baseplate 30 and have interdigitating,

0 forked guides 53, 54 and bear on stops of baseplate 30.

A sleevelike rubber spring 52 is held under initial stress by pins 49, 51 in the upturned lateral lugs of spring mountings 48, 50. A sole holder 32 is pivotally connected to a slide plate 56 by a pin 34 and bears on a guide cam 39 of a cover plate 31 by means of rollers 35, 37, which are mounted by pins 36, 38 in an extension 33 of sole holder 32. Slide plate 56 is disposed between the two upturned lugs of spring mountings 48, 50 and lies between their forked guides 53, 54 and the cover plate 31, which is secured to the surface of the ski together with the baseplate by screws 57, 58 so that a lifting of spring mountings 48, 50, slide plate 56 and sole holder 32 is prevented. Further means to prevent lifting comprise a further screw 59 for connection to the baseplate 30 and a shoulder pin 34 for guiding the sole holder 32 in a groove 60 of baseplate 30. Pin 34 is held against axial movement by its shoulder 63 and a lock screw 61. Slide plate 56 is held and guided by pins 42, 44, which are secured to this plate and mount rollers 43, 45, which are movable in guide slots 46, 47 of the cover plate 31.-

In response to forces acting transversely to the longitudinal direction of the ski, the sole holder 32 together with slide plate 56 can initially move transversely to the longitudinal direction of the ski and is guided in this movement by guides 39, 46, 47, 60. During this movement, the sole holder 32 bears by its rollers 35, 37 on guide cam 39 so that the sole holder cannot tilt. During the lateral movement, the slide plate 56 is moved against one of the spring mountings 48, 50 so that this mounting 48 or 50 is also displaced transversely to the longitudinal direction of the ski. As a result, the stress of rubber spring 52 is increased;

In this embodiment too, a friction-reducing layer 55 .is provided between forked retainers 53, 54 of spring mountings 48, 50 and baseplate 30 to facilitate the displacement of the spring mountings. As rubber spring 52 has a very low spring rate, the spring force opposing the displacement of spring mountings 48, 50, slideplate 56 and sole holder 32 is hardly increased even during a substantial movement.

When the foot has reached a predetermined angular position, the forwardly extending cam slot branches 40, 41 cause one of backing rollers 35, 37 of sole holder 32 to clear the guide cam 39 so that the sole holder 32 can perform a pivotal movement about the bolt 34 and the foot is released. The release position is shown in FIG. 8. In this case too, the spring element remains in engagement with slide plate 56 and sole holder 32 also in therelease position so that an automatic return to the initial position is ensured not only after slight lateral shocks but also after a release.

What is claimed is:

1. A toe iron for safety ski bindings comprising a base means attached to a ski, said base means being formed with a guide surface extending transversely to the longi- 4 tudinal direction of the ski, the length of which corresponds approximately to the range of foot-twist occurring during harmless lateral jolts, and terminating in guide faces which are inclined sharply forwardly to said transverse guide surface, a sole-retaining member carried by said base means, said sole-retaining member being positioned for movement along said guide surface and being biased by a return spring means carried by said base means and acting upon said sole-retaining member in every position to bias the sole-retaining member towards its normal sole retaining position, said return spring means comprised of two elements and a prestressed rubber tension spring having a very low spring rate secured therebetween, said two elements being slidable carried by said base plate and positioned for engagement with opposite sides of said sole-retaining member and stop means positioned so that one of said elements is carried along at a time by a movement of the sole-retaining member, whereas the other is retained in its initial position by stop means.

2. A toe iron according to claim 1, characterized in that each element includes a forkedangle member, which extends parallel to the surface of the ski and interdigitates with the other angle member.

3. A toe iron according to claim 2, characterized in that the sole-retaining member includes a driver plate, which is guided in said base means, and said driver plate serves for driving one angle member at a time.

4. A toe iron according to claim 1, characterized in that the sole-retaining member and said base means are each provided with at least two generally trapezoidal guide earns, which in normal position bear on each other with surfaces which extend transversely to the longitudinal direction of the ski, the guide cams of one part define between them a space for a guide cam of the other part.

5. A toe iron according to claim 1, characterized in that the sole-retaining member includes a sole-retaining element pivoted to a driver. plate, which is displaceable transversely to the longitudinal direction of the ski, and two backing rollers mounted on said sole-retaining element, in normal position the two backing rollers bear on a surface defined by said base means, which surface is cleared by one of the backing rollers at a time upon a predetermined transverse displacement.

References Cited UNITED STATES PATENTS 3,079,164 2/1963 De Place 280-4135 3,224,786 12/1965 Tosalli 280ll.35

BENJAMIN HERSH, Primary Examiner.

JAMES H. BRANNEN, Assistant Examiner. 

1. A TOE IRON FOR SAFETY SKI BINDINGS COMPRISING A BASE MEANS ATTACHED TO A SKI, SAID BASE MEANS BEING FORMED WITH A GUIDE SURFACE EXTENDING TRANSVERSELY TO THE LONGITUDINAL DIRECTION OF THE SKI, THE LENGTH OF WHICH CORRESPONDS APPROXIMATELY TO THE RANGE OF FOOT-TWIST OCCURRING DURING HARMLESS LATERAL JOLTS, AND TERMINATING IN GUIDE FACES WHICH ARE INCLINED SHARPLY FORWARDLY TO SAID TRANSVERSE GUIDE SURFACE, A SOLE-RETAINING MEMBER CARRIED BY SAID BASE MEANS, SAID SOLE-RETAINING MEMBER BEING POSITIONED FOR MOVEMENT ALONG SAID GUIDE SURFACE AND BEING BIASED BY A RETURN SPRING MEANS CARRIED BY SAID BASE MEANS AND ACTING UPON SAID SOLE-RETAINING MEMBER BEING POSITION TO BAIS THE SOLE-RETAINING MEMBER TOWARDS ITS NORMAL SOLE RETAINING POSITION, SAID RETURN SPRING MEANS COMPRISED OF TWO ELEMENTS AND A PRESTRESSED RUBBER TENSION SPRING HAVING A VERY LOW SPRING RATE SECURED THEREBETWEEN, SAID TWO ELEMENTS BEING SLIDABLE CARRIED BY SAID BASE PLATE AND POSITIONED FOR ENGAGEMENT WITH OPPOSITE SIDES OF SAID SOLE-RETAINING MEMBER AND STOP MEANS POSITONED SO THAT ONE OF SAID ELEMENTS IS CARRIED ALONG AT A TIME BY A MOVEMENT OF THE SOLE-RETAINING MEMBER, WHEREAS THE OTHER IS RETAINED IN ITS INITIAL POSITION BY STOP MEANS. 